System B0,+ amino acid transport regulates the penetration stage of blastocyst implantation with possible long-term developmental consequences through adulthood
| Autor: | Lon J. Van Winkle, Allan L. Campione, Julia K. Tesch, Anita Shah |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
medicine.medical_specialty
Amino Acid Transport Systems Motility Embryonic Development Fusion Regulatory Protein-1 Biology Mice Cell Movement Leucine Pregnancy Internal medicine medicine Conceptus Animals Humans Embryo Implantation Amino Acids reproductive and urinary physiology PI3K/AKT/mTOR pathway TOR Serine-Threonine Kinases Embryogenesis Uterus Obstetrics and Gynecology Placentation Trophoblast Embryo Biological Transport Cell biology Rats Trophoblasts Endocrinology medicine.anatomical_structure Blastocyst Reproductive Medicine embryonic structures Female Signal transduction Protein Kinases Signal Transduction |
| Zdroj: | Human reproduction update. 12(2) |
| ISSN: | 1355-4786 |
| Popis: | Amino acid transport system B(0,+) was first characterized in detail in mouse blastocysts over two decades ago. Since then, this system has been shown to be involved in a wide array of developmental processes from blastocyst implantation in the uterus to adult obesity. Leucine uptake through system B(0,+) in blastocysts triggers mammalian target of rapamycin (mTOR) signalling. This signalling pathway selectively regulates development of trophoblast motility and the onset of the penetration stage of blastocyst implantation about 20 h later. Meanwhile, system B(0,+) becomes inactive in blastocysts a few hours before implantation in vivo. System B(0,+) can, however, be activated in preimplantation blastocysts by physical stimuli. The onset of trophoblast motility should provide the physiological physical stimulus activating system B(0,+) in blastocysts in vivo. Activation of system B(0,+) when trophoblast cells begin to penetrate the uterine epithelium would cause it to accumulate its preferred substrates, which include tryptophan, from uterine secretions. A low tryptophan concentration in external secretions next to trophoblast cells inhibits T-cell proliferation and rejection of the conceptus. Suboptimal system B(0,+) regulation of these developmental processes likely influences placentation and subsequent embryo nutrition, birth weight and risk of developing metabolic syndrome and obesity. |
| Databáze: | OpenAIRE |
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